Audiology Tests for Balance Disorders

Vertigo can be scary - see your audiologist for diagnosis and management. washingtonpost.com

As the experts on the ear, audiologists have an important role in the evaluation and treatment of balance disorders. Our ears not only are responsible for hearing, but the inner ear structures are also responsible for helping us maintain our balance.

Case History

Often, a good case history is the most important diagnostic tool when it comes to balance disorders. The main concern should be identified, and characteristics of the balance disorder will be quantified.

It is important to note whether the balance disorder feels like a spinning sensation or dysequilibrium. Onset, type of symptoms, duration of symptoms, and an association of physical trauma (such as a head injury) are important clues to aid in diagnosis. Symptoms important to report are tinnitus, hearing loss, fullness or pressure in the ears, recent trauma or illness, and whether there is a family history of hearing loss, migraine or vertigo.

Hearing Evaluation

A hearing evaluation is often completed first as some balance disorders may cause changes in hearing sensitivity. A fluctuating low-frequency sensorineural hearing loss is associated with Meniere’s disease while a sudden sensorineural hearing loss may be due to vestibular neuritis or labyrinthitis. Tumors on the auditory nerve may first show up as absent acoustic reflexes before there is a noticeable change in hearing.

Office Tests

The audiologist may do an informal visual exam by having the patient perform basic neurological tests (visual tracking, finger to nose, finger to finger), postural testing (Romberg, tandem Romberg, Fukuda Step test), and/or look for motor control system abnormalities (gait disorders).

This testing may help the audiologist determine which formal tests will offer the most useful information.

ENG

Electronystagmography (ENG) is a test used to evaluate balance disorders by measuring eye movements. Electrodes measure eye movements while the patient performs tasks like:

  • visual tracking (ocular-motor evaluation)
  • body movements with eyes closed (positional tests)
  • caloric (water or air) stimulation of the ears.
  • rapid positioning tests (Dix-Hallpike)

The goal of ENG testing is to determine where the balance disorder is coming from; that is, whether the cause is central, peripheral, and/or if there is an imbalance between the balance systems of the left and right ear.

Dix-Hallpike

The Dix-Hallpike maneuver is part of the ENG battery but can be done independently of the ENG. The Dix Hallpike maneuver is completed by turning the head 45 degrees to the side and laying back quickly with the eyes open for the audiologist to observe eye movements. Rapid eye movements called nystagmus help the audiologist determine whether or not a particular type of vertigo called BPPV is present.

Platform Posturography

Posturography is an excellent supplement to the ENG test. This test measures how much a person’s body will sway when put into different scenarios that are designed to task the balance system. Unlike ENG, posturography also includes sensory-motor and visual contributions to maintaining balance.

Rotary Chair

In this test, the patient will wear infrared goggles to record eye movements during oculomotor testing (similar to the ENG) and for rotational testing. The rotary chair is considered the gold standard for diagnosis of bilateral vestibular loss and can be used to differentiate between balance problems associated with the vestibular system versus the central nervous system.

Sources:

Wippold FJ, Turski PA. Vertigo and Hearing Loss. American Journal of Neuroradiology. 2009 30: 1623-1625.

Posturography - Vestibular Technologies Home Page. (n.d.). Retrieved from http://www.vestibtech.com/Posturography.html

Rotary Chair Testing (n.d.) Retrieved from UCSF Medical Center http://www.ucsfhealth.org/education/rotary_chair_testing/

Shepard NT, Telian SA. Diagnosis | Vestibular Disorders Association. (n.d.). Retrieved from http://vestibular.org/understanding-vestibular-disorder/diagnosis

Zhang YB, Wang WQ. Reliability of the Fukuda stepping test to determine the side of vestibular dysfunction. J Int Med Res. 2011;39(4):1432-7

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